This invention relates to a pumping device for drawing in and delivering a liquid as, for example, a shaving aid, to a liquid dispensing device of a hair removing apparatus as, for example, a dry shaving apparatus, a hair clipping machine, or an epilation appliance, with a pump inlet, a pump outlet and a pumping element.
A pumping device for drawing in a lotion and dispensing it to the shaving head of a dry shaving apparatus is known from PCT WO 98/08661. The pump is comprised of a total of four components, including a housing part having a pump inlet and a pump outlet and integral flow channels, a membrane disk with nonreturn valves, a control disk, and a pumping element which is constructed from a membrane and designed to be actuated indirectly or directly by hand. It is an object of the present invention to simplify the pumping device of the type initially referred to, in particular to reduce the number of components. The pumping device should also be suitable for high pumping frequencies, i.e., for operation with an electric drive.
According to the invention this object is accomplished in a pumping device of the type initially referred to, wherein the pumping device is formed by a first and a second housing part having integrally formed therein flow channels as well as valve chambers and a membrane member disposed between the first and the second housing part and including a pumping element and at least one valve element, and that the pump inlet is adapted to be coupled to a liquid dispensing device and the pump outlet to a liquid container.
The pumping device of the invention has a plurality of advantages. One major advantage of the invention is that the pumping device is constructed from only three components. This results in a considerable saving of production costs.
According to one embodiment of the invention the pumping device is disposed outside a liquid container. According to a preferred embodiment of the invention the pumping device is disposed inside the liquid container.
A considerable saving of production costs results from one wall of a liquid container being constructed as a first housing part of the pumping device. The two other components, namely the membrane and the second housing part, are associated with this wall and secured to it. In a further aspect of the previously mentioned embodiment the membrane member arranged between the first housing part and the second housing part is of elastic construction.
A preferred embodiment of the invention is characterized in that the valve element and the pumping element are of elastic construction and provided as part of the membrane member. In a further aspect of the invention provision is made for the flow channel leading from a pump inlet to a pump outlet to be formed by a pump chamber and a first valve chamber and a second valve chamber.
An essential advantage of the invention results by designing the pumping device with the liquid container to be replaceable. Hence the efficiency of the pumping device is designed only for the quantity of liquid to be dispensed from the liquid container. The quality requirements to be imposed on the pumping device are therefore extremely low and result accordingly in an extremely economical production of the pumping device and the liquid container.